Boa cage setup questions

Hi everyone...I need some advice!

I am a (relatively) new snake keeper. I've had a western hognose and a Halmahera boa (candoia species) for about a year now and have their tanks set up thusly: cool hide and warm hide - warm hide is heated by a UTH and regulated by a Herpstat, with the probe placed in the hot hide, and a CHE placed over the hot side, with the probe on the cool side set to my ambient temp for the cage. Both snakes are eating, shedding and growing healthily so I'm pretty sure they are set up well. The specific temps differ for each species.

So now I just got a month old Hog Island boa. I initially set up his cage the same way as the others, with the appropriate temps. However, I've had him for a week and he has never once used a hide (great display snake!). I thought initially that the hides were too small so bumped them up a little in size but still he likes to chill in the open. Since he was using the hot side but OUTSIDE his hide, I figured I would just get rid of the hide on the hot side, and place the probe on top of the substrate there to make sure it was hot enough for him. Well...

My problem is that when the CHE comes on to warm the ambient temperature, the hot side shoots upwards of 97 degrees while it's on, which is too hot for the little guy, but if I lower the temp on the CHE then the ambient is too low. Obviously when the probe is in the hide it is shielded from the direct heat from the CHE, and without it it is exposed directly to the radiant heat from the CHE. This surface spike must also be happening in my other tanks, but the others don't seem too perturbed by it.

So, I thought OK I will just use the CHE to provide the hot spot and let the ambient take care of itself.....however if I keep the hot side at 91 using the CHE, over the course of the day the ambient side gets warmer and warmer to where it is over 86 degrees by the evening, and only drops to 84 at night. The room itself is much cooler, so the tank is just keeping the heat in.

To make things more confusing, he often hangs out on the hot side even though the temps spike so high.

So I guess my question is...should I put the hide back put the probe in it and stop worrying so much about this? Like I said the other snakes must be experiencing the same hot spikes but don't seem to mind, but since he never uses a hide I want to make sure the spots he IS using are perfect for him.

Long post, I know....thanks in advance.

Your thermostat probes should never be placed on or under the substrate where your snake can move them, pee on them, dump the water bowl on them, etc. That will give a falsely cool reading to the probe and then your appliance runs too hot.

Put the thermostat probe for the UTH between the UTH and the underside of the enclosure. Adjust the thermostat as needed so that the surface temp of the enclosure - not the temperature on top of the substate - as measured with a temperature gun or IR thermometer is correct for the critter. Put a thin layer of substrate over the warm surface and then the warm side hide on top. Snakes burrow and they will find the heat under that hide.

If you're running both the CHE and UTH on the one thermostat then yes you will have issues, they need to be regulated separately. If you don't have a separate thermostat for the CHE and you are only using it to maintain the ambient temperature, and the temperature in the room/house doesn't fluctuate, then you can use a lamp dimmer or rheostat to regulate it. You willl have to closely monitor it as well as be aware that the temperature will rise and fall with the room temperature. Or, you can put it on its own thermostat, let the probe hang down the cool side, and set the thermstat as needed for the species you're keeping in that enclosure. I keep mine on a thermostat since I don't run the HVAC much in the spring or fall, so the house ambient can vary a good bit even in 24 hours depending on the weather.

I have a Herpstat 4 running both independently so no issues there.

I have both my other snake cages set up the way I described, with the probe in the hot hides for the bask site and a probe affixed about an inch above the substrate for the cool/ambient temp, and for a year my temps have been perfect...I check them regularly with an IR temp gun and they are always within .1 of my target temp. I've never had a problem with overheating doing it this way and both snakes are thriving...by my perspective and that of my herp vet (who also owns snakes and set her cages up the same as I).

My problem with this little guy is that he doesn't use hides....neither the cold or the warm side and happily sleeps out in the open, so I figured I would place the probe where he would be to get an idea of what temps he is feeling.

I'm not sure how putting a temp probe outside the enclosure can accurately give you the temp inside the cage....perhaps I'm missing something?

For the under-tank heaters: sandwich the thermostat probe between the UTH and the underside of the enclosure. I start by setting the thermostat temp at 90*F and then bump it up or down from there as needed so that a temperature gun used to measure the surface temp on the bottom inside the enclosure reads 88-90*F for a boa. I expect a degree or so of heat loss due to the enclosure floor. If it's in the enclosure then your snake can move that probe off of the heat source.

The probes that control the CHE's should be fine hanging just above the substrate.

As for your boa not using hides... I have a 2015 baby that only uses his warm side hide when digesting, otherwise he is also out and about and doesn't use either hide. As long as he's eating, pooping, shedding, and not blowing snot bubbles I'm not concerned, he can pick the temperature he wants.

Ok thanks a lot! I'm going to give that setup a try and see what happens